m44 auto with 5spd diff ???

[dguzzardo22]

whats the revs going to be like ? any difference or whats the gearing going to be sluggish or how will my highway mpg be >

[familytruckster]

Probably burn the trans up from the load....That's a huge difference 4.44 to a 3.45. It will be SLOOOOOOOOW. Highway mpg will probably go down, it'll be jumping in and out of third and locking/unlocking the torque converter. Lot more load on it.

[dguzzardo22]

i thought i had read about someone who has done it for a temperay hwy mpg but idk how the city driving was

[dguzzardo22]

i have both diffs out and was just trying to search for that post but couldnt find it .

[familytruckster]

I shudder to imagine how horribly slow it'd be. City driving with that gearing would be worse for milage.

A 4.10 might help highway milage. 3.45 is too tall.

[dguzzardo22]

ill just wait till i do the full 5spd swap im trying to buy the seals and all so ill have everything with new seals and cleaned up.

[CirrusSR22]

Did it:
http://www.318ti.org/forum/showthrea...highlight=3.45

Summary, 1st gear is so low that it didn't make that big of a difference. Definitely no lugging at all.

My records show I drive like this for over a year before I actually did my manual swap. Didn't seem like that long, but it must have been no big deal as I left it there. I also don't remember having any major MPG improvements either, so that must have been a wash. Can't believe I never updated that thread.

Anyway, if you're doing it for MPG, I say don't bother.

[dguzzardo22]

So is it not worth it or no differences or ? Pointless to even try find out ?

[bryan413]

Originally Posted by familytruckster

Probably burn the trans up from the load....That's a huge difference 4.44 to a 3.45. It will be SLOOOOOOOOW. Highway mpg will probably go down, it'll be jumping in and out of third and locking/unlocking the torque converter. Lot more load on it.

Nah its not a big deal. GM uses all different rear end ratios on their trucks with the same transmissions.